1. Field
The present disclosure relates to a cathode, a lithium air battery including the same, and preparation methods thereof.
2. Description of the Related Art
A lithium air battery includes an anode capable of intercalating and deintercalating lithium, a cathode that oxidizes or reduces oxygen in the air, and an electrolyte disposed between the anode and the cathode.
Since the lithium air battery uses lithium metal as an anode and does not have to store the cathode active material (i.e., oxygen in the air) within the battery, the lithium air battery may have high capacity. A lithium air battery has a high theoretical energy density per unit weight of 3,500 Watt-hours per kilogram (Wh/kg) or greater, which is about ten times greater than that of a lithium ion battery.
It has been disclosed that a concentration gradient of oxygen occurs within a porous cathode, and that the concentration of oxygen is decreased in an area adjacent to a separator. Thus, due to the low concentration of oxygen in the area adjacent to the separator, a discharge capacity of the cathode may be limited. In order to increase the concentration of oxygen that is delivered to the inside of the cathode, a porosity of the cathode may be increased. However, in regard to the cathode having improved porosity, impregnation of the electrolyte is increased, and accordingly oxygen delivery may be blocked.
Therefore, there is a demand for methods of improving the discharge capacity of the lithium air battery by increasing the concentration of the cathode active material without increasing impregnation of the electrolyte within the cathode.